This application seeks to supplement the on-going research grant entitled, "Bilingual Preschoolers: Precursors to Literacy" (5 R01 HD39496-03) funded for five years by the joint NICHD/OERI biliteracy research initiative, Development of English Literacy in Spanish Speaking Children (DELSS). This prospective longitudinal investigation is currently beginning its third year and is designed to improve our understanding of the language and literacy development and home environment of Head Start children of Puerto Rican descent by (1) determining if the rate and quality of speech, language and literacy development of children learning Spanish and English sequentially differs from that of children learning both languages simultaneously; (2) identifying the individual differences in oral language and the home environment that lead to better literacy outcomes; and (3) describing in-depth the characteristics of children's linguistic systems that are associated with literacy outcomes and qualitative aspects of the home environment that mediate between the children's linguistic systems and literacy outcomes. This supplemental application proposes to extend the first two aims of the parent grant by studying children's language and reading development and home environment during first and second grades. It also expands the second question to include a study of the classroom-reading environment and its relationship to reading outcomes. The data will provide greatly needed longitudinal information about the course of bilingual children's language and reading development across a 4 and 5 year period and result in an understanding of the relationships among children's language abilities and home environment during their preschool years and reading outcomes during early elementary school years. The addition of classroom data allows for exploration of the relationships between classroom variables and reading outcomes of bilingual children who have varying language characteristics and home environments. [unreadable] [unreadable] [unreadable]